Wednesday, June 17, 2009

I recently read an article by the Boston Globe discussing the recent crash of Air France flight AF 447. This article (by a Globe staff writer, not an aviation professional or an engineer) is attempting to solve a plan crash that happened in 2001, suggesting composite materials may be to blame for that crash, and furthermore, may be to blame for the recent Air France Airbus crash. (Sites no sources)

Composite materials are helping the avaition industry save fuel, and this is directly effecting passengers and the enviroment. Articles such as this delay the general public acceptence of composites at an ever important time. The weight saving advantages of composite materials is slowly finding acceptence in automotive and rail. Some of the worlds brightest engineers design, test, and re-test composite components to an extreme.

Fear helps sell newspapers, and that is exactly what this author was trying to install.

2 comments:

This is an account of a discussion originally posted by George Larson, Editor emeritus ofSmithsonian Air & Space Magazine:

"I had recently with a maintenanceprofessional who salvages airliner airframes for a living. He hasbeen at it for a while, dba BMI Salvage at Opa Locka Airport inFlorida. In the process of stripping parts, he sees things few othersare able to see. His observations confirm prior assessments ofAirbus structural deficiencies within our flight test and aerostructures communities by those who have seen the closely held reportsof A3XX-series vertical fin failures.

Airbus products are the flimsiest and most poorly designed as far asairframe structure is concerned by an almost obsession to utilizecomposite materials.

I have one A310 vertical fin on the premises from a demonstration Ijust performed. It was pathetic to see the composite structureshatter as it did, something a Boeing product will not do.

The vertical fin along with the composite hinges on rudder andelevators is the worst example of structural use of composites I haveever seen and I am not surprised by the current pictures of rescuecrews recovering the complete Vertical fin and rudder assembly atsome distance from the crash site.

The Airbus line has a history of both multiple rudder losses and avertical fin and rudder separation from the airframe as was the casein NY with AA.

As an old non-radar equipped DC4 pilot who flew through many athunderstorm in Africa along the equator, I am quite familiar withtheir ferocity. It is not difficult tounderstand how such a storm might have stressed an aircraft structureto failure at its weakest point, and especially so in the presence ofinstrumentation problems.

I replied with this:

"I'm watching very carefully the orchestration of the inquiry byFrench officials and Airbus. I think I can smell a concerted effort tosteer discussion away from structural issues and onto sensors, etc.Now Air France, at the behest of their pilots' union, is replacingall the air data sensors on the Airbus fleet, which creates adistraction and shifts the media's focus away from the real problem.

It's difficult to delve into the structural issue without wading intothe Boeing vs. Airbus swamp, where any observation is instantlytainted by its origin. Americans noting any Airbus structural issues(A380 early failure of wing in static test; loss of vertical surfacesin Canadian fleet prior to AA A300, e.g.) will be attacked by theother side as partisan, biased, etc. "

His follow-up:

One gets a really unique insight into structural issues when one hasfirst-hand experience in the dismantling process.

I am an A&P, FEJ and an ATP with 7000 flight hours and I wasabsolutely stunned, flabbergasted when I realized that the majority ofinternal airframe structural supports on the A 310 which appear to bealuminum are actually rolled composite material with aluminum rodends.They shattered.

Three years ago we had a storm come through, with gusts up to 60-70kts., catching several A320s tied down on the line, out in the open.

The A320 elevators and rudder hinges whose actuators had been removedshattered and the rudder and elevators came off.

Upon closer inspection I realized that not only were the rear sparscomposite but so were the hinges. While Boeing also uses compositematerial in its airfoil structures, the actual attach fittings forthe elevators, rudder, vertical and horizontal stabilizers are all ofmachined aluminum."